Tooth whitening recovers the color of pre-stained composites

Abstract

Aim: To assess the effect of home-whitening on aged and stained composite. Methods: Fifteen discshaped specimens (10 mm diameter x 2 mm thick) of Filtek Z350XT, shade A2E were fabricated, polished and embedded in wax, leaving exposed the top surface. The specimens were allocated to three groups (n=5): A -the specimens remained dry; B -conditioning in distilled water and; C -conditioning in distilled water and coffee. They were next subjected to whitening with 10% carbamide peroxide (Whiteness Perfect) for 4 h daily for 1, 2 and 4 weeks. Shade was measured with a spectrophotometer Easyshade and expressed based on the CIE L*a*b* system (ΔE*). Surface roughness was measured with a roughness meter (Ra-µm). Data were analyzed with two-way ANOVA and Tukey's test (α=0.05). Results: Conditioning, grouping and the interaction between both, influenced the ΔE* (p<0.0001), which exceeded the 3.3 threshold for visible color change after conditioning of Group C in black coffee. Whitening for 1 week significantly reduced ΔE* in this group. There were no significant changes in surface roughness. Conclusions: Home-whitening did not alter significantly the color of the nanocomposite, except when it was previously stained. One-week whitening was sufficient to recover color change to an acceptable level.

Effect of whitening mouth rinses on the chemical and physical properties of a nanofilled composite

“…The color of tooth-colored restorations is usually a concern after tooth whitening, requiring a restoration replacement after tooth whitening is finished 13 . Recent studies showed that perceptible color change (∆E*) might be induced by tooth whitening substances when extrinsically acquired stains are impregnated in the restoration 12,25 . However, lower thresholds were set recently for 50%:50% perceptibility and acceptability of color change.…”

“…It is noteworthy that the presence of 2.5% hydrogen-peroxide in Listerine Whitening Extreme did not play a role in color change, producing the lowest nominal ∆E* value of all groups. This lack of significant influence of a whitening substance in the mouth rinse may again be explained by the absence of extrinsic staining agents in the composite resin 12,25 , causing minimum color changes and unlikely presenting clinical significance 25 . The overall color change was mainly driven by the reduction in a* and b* axes values, which leads to color changes towards green in the a* axis and towards blue in the b* axis.…”

“…The hydrogen peroxide present in some whitening mouth rinses has produced a whitening effect on previously stained composites 12 . This occurs when the whitener breaks dark complex molecules of pigment into simpler structures with lighter optical properties 12 .…”

“…The hydrogen peroxide present in some whitening mouth rinses has produced a whitening effect on previously stained composites 12 . This occurs when the whitener breaks dark complex molecules of pigment into simpler structures with lighter optical properties 12 . It is noteworthy that a significant whitening effect only occurs in the presence of acquired extrinsic stains and it is not an issue when the composite is not extrinsically pigmented 12,13 .…”

“…This occurs when the whitener breaks dark complex molecules of pigment into simpler structures with lighter optical properties 12 . It is noteworthy that a significant whitening effect only occurs in the presence of acquired extrinsic stains and it is not an issue when the composite is not extrinsically pigmented 12,13 . According to Goldberg et al 14 (2010), hydrogen peroxide increases the leaching of components from amalgam and fluoride-containing restorative materials, affecting the bond interface between composite and bleached dentin.…”